The evidence for the use of cryotherapy to reduce edema and inflammation is
overwhelming. The evidence for the use of heat to facilitate MER is just the
opposite. Because engorgement is edema, why would we use heat? The research on
heat shows it increases swelling. Why would we want to do that to a woman who
is already in pain? Ice, properly applied (15 mins on, 45 mins off), both
reduces swelling and increases circulation. When the swelling is taken care
of, the milk is able to move.

The other part of this is to keep the signals to make milk and move lymph
intact. You do this by getting the baby to breast, and if the baby can't or
won't, by pumping or manual expression. The lymph vessels respond to oxytocin
(the vessels are smooth muscle fiber) and will contract. Once they start
contracting as they should, they act as a vacuum and pull waste material from
the extracellular space which in turn reduces swelling.

So the recipe is: get the milk moving with baby or mecahnical expression and
reduce the swelling with cryotherapy.

Whoever started us in thinking that heat would "thin the milk and make it
flow" was expressing their opinion. It may have made sense to them at the time
but it really doesn't make sense now with all that we now know about lactation
physiology.

As challenging as it is to change our practice and to have our beliefs
questioned, we must do it. Next year, we'll have more information that will
cause us to reexamine what we learned last year, and so it goes.

Alison K. Hazelbaker